1. Field of the Invention
This invention relates to a composite-figure definition method and, more particularly, to a composite-figure definition method for combining already defined first and second figures to define a new figure.
2. DESCRIPTION OF RELATED ART
In an automatic programming system for creating NC data using an automatic programming language such as APT (automatic programming tools) or FAPT,
(a) a part program based on the automatic programming language is created by defining points, straight lines and circular arcs using simple symbols (this is referred to as "figure definition"), defining a profile using the defined points, straight lines and circular arcs, and then defining a tool path along the profile (referred to as "motion statement definition"), and
(b) the part program based on the automatic programming language is subsequently converted into NC data comprising NC data (EIA codes or ISO codes) in a format capable of being executed by an NC unit.
For example, in the creation of a part program for moving a tool along a part profile 1 comprising straight lines S.sub.1 -S.sub.4 shown in FIG. 10, figure definition is performed by defining straight lines S.sub.1 -S.sub.4, which are necessary for defining the part profile 1, as follows using a keyboard or tablet: ##EQU1##
Thereafter, these defined figure elements (which are displayed on a CRT screen) are picked in order, e.g., EQU S.sub.1 .fwdarw.S.sub.2 .fwdarw.S.sub.3 .fwdarw.S.sub.4
to define the part profile 1, and then machining starting and end points, etc., of the part profile 1 are designated by motion statement definition to define a tool path along which a tool is moved.
In the creation of a part program for moving the tool along a part profile 2 comprising straight lines S.sub.6 -S.sub.8 shown in FIG. 10, figure definition is performed by defining straight lines S.sub.6 -S.sub.8, which are necessary for defining the part profile 2, as follows: ##EQU2## Thereafter, these defined figure elements are picked in order, e.g., EQU S.sub.6 .fwdarw.S.sub.7 .fwdarw.S.sub.8
to define the part profile 2, and then a tool path is defined by motion statement definition.
In the foregoing,
(1) signifies a straight line parallel to the Y axis and whose X intercept is x.sub.1 ; PA1 (2) signifies a straight line parallel to the X axis and whose Y intercept is y.sub.1 ; and PA1 (5) signifies a straight line passing through coordinates (x.sub.3,y.sub.3) and (x.sub.4,y.sub.4).
In defining a part profile, there are instances where figures (profiles) already defined are combined to define a new figure. Even in a case such as this, the prior art is such that the figure elements constituting the profiles must be defined one at a time, after which the elements constituting the profiles must be designated in order, as set forth above.
By way of example, assume that a new FIG. 3 (FIG. 11) is defined by combining the already defined first FIG. 1 and second FIG. 2 shown in FIG. 10. In such case, straight-line elements S.sub.i must be designated one at a time in order, namely in the manner S.sub.1 .fwdarw.S.sub.2 .fwdarw.. . . .fwdarw.S.sub.8, along the profile of the desired combined figures by means of a graphic cursor GCS.
Thus, a problem with the composite-figure definition method of the prior art is that despite the fact that the basic figures are already defined in terms of profile, the profile definitions of the basic figures cannot be utilized.
Accordingly, an object of the present invention is to provide a composite-figure definition method in which the profile definitions of basic figures can be utilized to enable composite definition of figures quickly and easily.